Safety electric switch.



" No. 842,843. PATENTED JAN. 29, 1907. r

A. H. WILLIAMSON. SAFETY ELECTRIC SWITGH.

APPLIOATION FILED FEB.3, 1906.

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ARTHUR HAROLD WILLIAMSON, OF LACHINE, QUEBEC, CANADA.

SAFETY ELECTRIC swlroH.

'. Specification of Letters Patent.

Patented Jan. 29, 1907.

Application filed February 3, 1906. Serial No. 299,231.

provements in SafetyElectric Switches, of

which the following is a full, clear, and exact description.

My invention relates to safety electric switches; and the object is to provide a simple and easily-operated switch that will be so constructed as to preclude any possibility of burning or otherwise injuring the operator. To accomplish this object, l provide a casing of insulating material containing the switch mechanism and having a protected knob or handle protruding therefrom. The casing may be set in a wall or in any other convenient place and the protected handle operated with perfect safety.

-In' the drawings which illustrate my invention, Figure 1 is a perspective view of the device, showing the'casing and interior mechanism. Fig. 2 is a sectional elevation of the operating-handle containing the protecting device. Fig. 3 is a perspective view of the switch-blades. Fig. 4 is a perspective view showing the top of the device as it would appear when set in a wall.

Referring to the parts, 1 designates a cas ing of insulating material, such as fiber or vulcanite. v I

2 designates the positive poles of the switch, each supported'on a suitable base and comprising upright'imembers, as shown in Fig. 1. 3 designates similar negative poles, and 4 switch-blades having slots 6 at one end and notches 7 at the opposite end. The blades are rigidly connected by means of an insulating cross-piece 8 and are adapted to slide longitudinally-on the bolts 9, con-- nccting the sides of the posts 2. The notches 7 in the op osite ends of the switch-blades are adapte to engage the connecting-bolts lO of the negative oles 3..

ll designates a t readed-post sup orted on the insulating member 8' and is a apted to extend uplwardly through a slot 14 in the cover off e casing.

12 designates a guard of suitable material for the knob or handled the switch. The guard 12 is laced over the slot 14 and has an integral s save 13, ad'apted'to receive the post 11. casing keeps the guard secured in position.

A spring 16, surrounding the post 11 be- A nut '15 under the cover of the tween the cover of the casing and the member 8, is adapted to keep the switch-blades 4 securely. in engagement with the poles 3.

17 designates a plate which may be fastened to the cover of the casing, if desired.

dle adapted tobe screwed to the post 11 above the guard 12.

19 represents line-wires entering the casing and fastened to the poles in the usual manner.

It will be obvious that when the parts are assembled in position and the switch closed into engagement with the forked ends of the poles 3, so that the notches 7 will engage the pins 10. When it is desired to open the switch, the knob is drawn upwardly against the spring and at the same time slid in the slot 14 until the ends of the switch-blades are outof engagement with the posts 3. The switch-blades will have a longitudinal sliding motion andat the same timea pivotal movement on the pins 9, which will facilitate rapid breaking of the circuit. The notches 7 will serve to prevent the blades being disengaged by jarring or other means from the pins 10. The projecting-plate 12 will effectually prevent any flashes escaping through the slot to injure the operator. Having thus described my invention, so that'the same may be readily understood by those skilled in the art to which it appertains, what I claim, and desire to secure by Letters Patent, is Y 1. In an electric switch, a casing of insulating material, terminal poles mounted in said casing, switch-blades slidably mounted on one pair of poles and havin notches sulating member connecting said switchblades, a threaded post mounted on said insulating member, and a helical s ring sur rounding said post adapted to maintain the I 2. In an electric safety-switch, a casing of lnsulatlng mater al, terminal poles mounted pivotally and slidably mounted on one pair of terminalpoles, said switch-blades having notches in their opposite ends adapted to engage a second pair of terminal poles, an in sulating member connecting said switchblades, a threaded post mounted on said insulating member, and adapted to operate in a slot in the cover of said casing.

the spring 16 will force the switch-plates a 3.

adapted to engage the opposite po es, an in-'.

in said casing, a pair of slotted switch-blades 18 is an internally-threadcd knob or hanswitch-blades in engagement with the poles.

3. In an electric switch, a casing, terminal poles mounted therein, slotted switch-blades slidably and pivotelly mounted on one pair of terminal poles, notches in the ends of said switch-blades adzipted to engage a second pair of tenninnl poles, an insulating member connecting said .SWltUlkblitt'lOS, a threaded post ineunted in said insulating; member, a coinpression-spi'ing surrounding said post, it handle mounted on ssid pust, and a guardplnte mounted lwnesth said handle.

4. 1n a device oil the class described, 21, cu-s ing, terminal poles mountid therein, slotted switch-blades pivoted to one pair of terminal poles endndnpted to slide in and. out of engztgement with the second pair of terminal poles, an insulatlng member connecting stud. l

switch-blades, a post mounted in said insua leting member adapted to o erate in a slot in'a cover of the casing, a he ical spring surrounding suid post, a guard-plate mounted on said post above the slot, and a handle of insulating material lemovably mounted on the extremity of said post.

In witness whereof I have hereunto set my l a hand in the presence of two Witnesses. AR'lllUlt HAROLD WILLIAMSON.

Witnesses: I l D. W. S1. MARTIN,

v J. ANDERSON BISHOP. 

